For 600pts I would suggest swapping your captain for Mauhur (expensive model though) as his extra attack and swift movement make him quite deadly plus he comes with an extra might point.

Hey there,

First, your army list.
From what I see your list looks ok you might be able to hone it a bit sharper with a few small changes.
First up what pts do you normally play? 617 seems a bit random lol, second, are these the only models that you have or can you change it up a bit?

For 600pts I would suggest swapping your captain for Mauhur (expensive model though) as his extra attack and swift movement make him quite deadly plus he comes with an extra might point. Alternatively sit your own captain at the back and declare him your General, his D7 may help in keeping him alive.

As far as your warriors go I'd suggest drop some shields, to add some pikes and take your maximum (or close to) number of crossbows. The added missile fire should mean that you are not automatically having to march towards the elves making things more even. The added pikes should means that you can bring more attacks onto the enemy.

Its good that you have a shaman and a banner as both are very useful (well shaman almost essential)

In regard to the fighting itself, my big question is how are you using the list?
What is it that seems to make victory fall out of your grasp? Is your opponent butchering you at range, is he smashing through your lines in combat, forever dancing out of reach or outflanking you on all sides. If you can understand what it is that's going wrong you can be ready to counter it.

With a heavily armoured uruk force your main strengths are that you have very strong infantry each capable of taking pain and dishing it out. An uruk-hai vs an elf in combat can be pretty even because the elf has a higher chance of winning but the uruk more chance of wounding (assuming he has a shield, though also be wary of the phalanx formation as your front warriors can be trapped quite easily). Make sure that the shields fill up your front rank with at least one rank of pikes behind. If from there you have your crossbowmen running around the sides with the beserkers you should find that his elves are being stretched to cover all of the angles.
Keep that shaman behind your army at all costs and keep him alive. As long as he is alive and within 6inches of another hero you can usually make your whole army immune to running away (generally anyhow). His ability to keep uruk-hai alive is cool but its the auto pass on courage that you take him for.
Also do not be shy of throwing vrasku or your crossbows into combat. They're all decent fighters and when things get close your better hitting the elves in the face than shooting through your own men.

You've also mentioned that your opponent is more experienced. That really is invaluable in winning games, past experience. Only way you can get it is to keep playing, but also ask your opponent his opinion at the end of a match. I've been playing wargames for years and like to think I'm a decent player but whenever I lose I talk with my opponent about what went wrong, what I could have done differently. Can add a lot of perspective.

Anyhow best of luck and hope this helps.